Kate

Kate is a modern text editor built on KDE Frameworks and Qt, available for Linux, Windows, and macOS. It supports simultaneous editing of multiple files through tabs and split views, and includes a project sidebar for navigating directory structures. The editor offers syntax highlighting for over 400 languages, bracket matching, on‑the‑fly spellchecking, and configurable hotkeys.

Productivity features include multi‑cursor and multi‑selection editing, a powerful search‑and‑replace tool that works across entire projects, and an integrated terminal emulator for running console commands without leaving the editor. Kate also provides a preview plugin for Markdown, HTML and and SVG, as well as plugins for SQL queries, debugging with GDB, and one‑click project builds.

For developers, Kate incorporates language‑server‑protocol based autocompletion, scriptable auto‑indentation, VI input mode, rectangular block selection, and smart comment handling. The extensive default plugin set and customizable key bindings make it suitable for complex coding tasks and general text editing alike.